Ticket to Ride: the Physics of Extreme Machines

Who among us doesn't yearn to experience, even briefly, the sensation of weightlessness in space? Small wonder, then, that Jen-Luc Piquant is excitedly pinching her virtual pennies, hoping to save up enough for a spot on the new extreme roller coaster being designed by a company called BRC Imagination Arts.

The twist: the design mimics elements of the flight path typical of NASA"s infamous "vomit comet" to create a simulation of microgravity lasting a full nine seconds. (Blame the folks at io9 for getting her all worked up with their post about it.) According to Popular Science:

"To create that illusion, a linear induction motor system would speed coasters up the track with unprecedented precision. As the coaster approached a top speed of more than 100 mph, it would suddenly and ever so slightly decelerate-just enough to throw the passengers up from their seats, like stones from a catapult-and then quickly adjust its speed to fly in formation with and around the passengers. (The ride's calculations would correspond to the unique heft of any particular group.)"

"As the coaster reached the top of the track and began to drop back down, the computer system would continue to match its speed to that of the falling passengers, extending the sensation of weightlessness for several additional seconds, and finally rapidly decelerate to a stop back at the base station."

Jen-Luc will be pinching those virtual pennies for a good long while, alas, because the exhilaration comes with a hefty price tag: it should cost around $50 million to build the zero gravity coaster, and the company will need to recoup those costs in its tickets. The Vomit Comet fares run around $3500, and those are under-written by NASA. I believe she is hoping that Ashton Kutcher -- the latest celebrity to book passage on Virgin Galactic -- will become enamored of her pixelated charms and treat her to the experience on their memorable first date. (Jen-Luc is a tad bit delusional at times.)

Extreme coasters are all the rage these days. Japan, for instance, boasts the world's steepest roller coaster, which debuted last year. The Takabisha accelerates to 100 mph, has a 43-meter drop and a 121-degree freefall. It lasts 112 seconds and fares are $12.50, so that's quite a bargain compared to the zero gravity version.

And earlier this month, TIME reported on a brand-new coaster called The Swarm at London's Thorpe Park, a winged ride in which riders' arms and legs dangle freely, and featuring an inverted drop of 127 feet. Most noteworthy: the ride is purportedly so gut-wrenching that even hardened former RAF fighter pilots blanched a bit.“ You really do feel as if you are going to crash into the structures,” one such former pilot admitted. Oh, and the ride tore a few crash test dummies to pieces during testing. Good times.

But nothing's quite so extreme as a fascinating project undertaken by the fine folks at Design Interactions Research, an organization that "focuses on exploring interactions between people, science and technology on many different levels." This particular "interaction" is the brainchild of Julijonas Urbonas, a designer, artist, engineer and PhD student specializing in the "gravitational aesthetics" as played out in "gravitational theater." He is also managing director of a Lithuanian amusement part, so it's only natural that his project is called the Euthenasia Coaster. As he describes it:

“Euthanasia Coaster” is a hypothetical euthanasia machine in the form of a roller coaster engineered to humanely – with elegance and euphoria – take the life of a human being. Riding the coaster’s track, the rider is subjected to a series of intensive motion elements that induce various unique experiences: from euphoria to thrill, and from tunnel vision to loss of consciousness, and, eventually, death."

"Thanks to the marriage of the advanced cross-disciplinary research in aeronautics/space medicine, mechanical engineering, material technologies and, of course, gravity, the fatal journey is made pleasing, elegant and meaningful. Celebrating the limits of the human body, this ‘kinetic sculpture’ is in fact the ultimate roller coaster: John Allen,former president of the famed Philadelphia Toboggan Company, once said that “the ultimate roller coaster is built when you send out twenty-four people and they all come back dead. This could be done, you know."

That's right: A Killer Coaster! And if you're wondering whether an amusement park ride could really be all that lethal -- yes, it can, depending on the coaster's design, and Urbanos has deliberately designed his coaster to maximize the kinds of adverse physical effects other coaster designers seek to minimize. (Discovery has a terrific Website where you can try your hand at designing your own coaster.)

It's not just about speed; you need a smooth ride. Early roller coasters moved very slowly compared to modern scream machines, but even at slow speeds, a simple loop-the-loop can cause whiplash and other neck and back injuries. In 1885, the Flip-Flap debuted with a 25-foot diameter loop-the-loop, but it closed in 1903 because of all the injuries suffered by passengers because of the sharp, jerking motions. There's a reason modern looping coaster designs incorporate a teardrop shape; it minimizes the forces that cause such havoc with the human body.

Speed can certainly be a factor, as in the infamous encounter in 1999 between male model Fabio and a wild goose. Busch Gardens in Williamsburg, Virginia, brought in Fabio for the opening of the park’s new roller coaster, Apollo’s Chariot -- he of the flowing blond locks, chiseled jaw and impeccably sculpted torso, best known for posing in strategically ripped shirts on the covers of mass-market romance novels, and for hawking butter substitutes on TV. And Fabio was game. But halfway through the initial 210-foot drop, a wild goose flew into the coaster’s path and smashed into Fabio’s face. The impact gashed the model’s nose and killed the goose, whose broken body was later fished out of a nearby river. Fabio ended the ride with his face covered in blood.

Blame those nasty “G forces": a unit for measuring acceleration in terms of gravity that tells you how much force we are actually feeling. A roller coaster is constantly accelerating -- forward and backward, up and down, side to side -- so you get variations in the strength of gravity’s pull. For example, 1G is the force of Earth’s gravity: what the rider feels when the car is stationary or moving at a constant speed. Acceleration changes the equation. At 4 Gs, for example, a rider will experience a force equal to four times his weight.

Poor Fabio endured a lot of ridicule after his encounter with the kamikaze goose; people were amused that the 6’3”, 220-pound hunk fared so poorly against a 22-pound waterfowl. But assuming the collision lasted a hundredth of a second, and the coaster was traveling at a speed of about 70 MPH, Fabio would have absorbed the impact equivalent of a hard tackle by football hall-of-famer Mean Joe Green, delivered with a force equivalent to a solid punch from heavyweight champ Mike Tyson. Yet not one reporter ever said, “That Fabio, he can really take a punch!”

So yeah: your roller coaster has a dark side: accidents and injuries do happen, and coaster-related (human) deaths number between two and four per year. This might seem insignificant; fatalities occur for about one in 450 million riders. But the newest coasters can reach top speeds of 100 MPH with G force ratings as high as 6.5.

For comparison, astronauts typically experience 4 Gs while traveling up to 17,440 MPH on liftoff, and NASCAR drivers have reported feeling dizzy after experiencing 5 Gs. Coaster designers counter this by pointing out that astronauts and NASCAR racers experience sustained G forces; roller coaster riders are typically only exposed to high G forces for one second or less.

Of course, one can't completely discount human stupidity, either. Some of the most spectacular accidents occur because riders ignore basic safety precautions. Removing the safety harness can chuck a rider out of the car and send him flying through the air at high speeds. In 1996, at Six Flags Great America, a man wandered into a restricted track area to retrieve his wife’s hat, which had blown off in the high winds. A rider on the Top Gun suspension coaster kicked him in the head, killing the man instantly. The rider suffered a broken leg.

But the Euthanasia Coaster seems to focus on the more insidious kinds of physical effects; some doctors believe that the sharp jerks and jostles of high-speed rides could have the same brain-battering effects as professional football. The strong G forces can cause headaches, nausea and dizziness – possibly harmless, but also symptoms of mild concussion – simply because the body doesn’t have sufficient time to adapt to the constantly changing environment.

The effect can be similar to what happens to the brain during a car accident, or when a person is violently shaken. As the head whips sharply back and forth, the brain can pull away from one side of the skull and smash into the other side with sufficient force to rupture tiny blood vessels. The trickling blood accumulates in the small space between the brain and the skull, and the resulting pressure can lead to permanent brain damage or death if left untreated. In the summer of 2001 alone, three women suffered fatal brain injuries on roller coasters in California, although two of those victims had pre-existing aneurisms – a weak spot on a blood vessel in their brains – which ruptured during the ride.

None of these dangers are likely to dissuade any diehard coaster fans; that's just another part of the thrill. But take it from Fabio: a roller coaster can definitely hurt you. And the Euthanasia Coaster literally wants to kill you. At least first, it will give you the ride of your life.

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